The temperature sensors of JP-A-2001-56256 and JP-A-5-264368 are known in the related art. These temperature sensors are individually provided with: a housing; a thermo-sensitive element housed in the housing for outputting electric characteristics varying with the temperature, as an electric signal; and a pair of lead wires connected at their one-side ends through a pair of core wires with the thermo-sensitive element for extracting the electric signal from the thermo-sensitive element to the outside of the housing. The temperature sensor of JP-A-2001-56256 uses SUS wires (or stainless steel wires) as those lead wires, and the temperature sensor of JP-A-5-264368 uses copper wires (or nickel-plated annealed copper wires).
According to these temperature sensors, the thermo-sensitive element has its electric characteristics changed by the atmospheric temperature, so that the electric signal corresponding to the change is transmitted through the two core wires to the two lead wires and is obtained from a connector connected with the individual other ends of the two lead wires. These temperature sensors are used for detecting the temperature of the exhaust gases or the like of the vehicle.